Rail welding apparatus incorporating rail restraining device, weld containment device and weld delivery unit

ABSTRACT

A rail restraining ( 1 ) and weld delivery device ( 100 ) uses a frame for supporting a welding head with a clamp ( 3 ) for restraining a first rail end and a second rail end and a base twist assembly ( 17 ) for aligning said first end and second end. An interconnected weld containment apparatus ( 290 ) pivotally connects to the clamp by use of a cam actuated linear pin ( 7 ). This arrangement is operable in an environment in which clearance between rails is about 7 to 11 inches and sufficiently compact that it may be operated from and carried in a truck based on a standard over the road truck.

CLAIM OF PRIORITY

Priority is claimed based on Provisional Application Ser. No.60/069,795, filed Dec. 16, 1997, which is incorporated by reference asif fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention is as described herein and shown in the accompanyingdrawings is for a rail welding apparatus incorporating a railroad railrestraining device, weld containment device and weld delivery unithaving improved rail restraining characteristics, improved weldsupporting properties and being compact, lightweight and economical forgreater utility. The restraining device enables the positioning of railends of either long prewelded rails, special rail sections forappliances such as in frogs or turn-outs or switches, existing rails inneed of repair, or a combination of these. Because of the high strength,improved geometry and design, the device can be utilized in the gas-arcwelding of highly restricted clearance rail splices or joints, such asin welding a length of rail to a turn-out assembly.

2. Description of Related Art

In the prior art, there are three main ways to weld railroad track.These include aluminothermic welding (U.S. Pat. Nos. 5,215,139 and5,306,361), flash-butt welding (U.S. Pat. Nos. 4,929,816; 5,270,514; and5,469,791); and gas-arc welding (U.S. Pat. No. 5,605,283). These allhave certain advantages and disadvantages. Aluminothermic welding haslow equipment requirements, is economical to perform but produces weldsof less strength than the other methods. Flash butt welding uses complexequipment but produces high strength welds, however it is difficult touse to join rails in the field, and results in a loss of rail length,which can cause difficulties. Gas-arc welding requires precise alignmentand a considerable length of time to perform a weld of sufficientstrength, heretofore also requiring equipment of considerable size,complexity and cost. The invention enables the use of gas-arc weldingwith greater ease and lower cost.

SUMMARY OF THE INVENTION

The rail restraining device, weld containment device and weld deliveryunit of the invention needs to handle rail sections often as long asone-quarter mile, aligning rail ends precisely for welding, yet can bemade sufficiently compact to be incorporated on a hi-rail equippedover-the-road truck or shipping container on a chassis or car havingeconomy and requiring no special licensing or equipment forover-the-road use while being sufficiently small sized itself to fit inthe space available to weld rails even to switch or turnouts or in frogswhere the weld joint is separated from the adjacent rail portion by aslittle as about 7″ to 11″.

The rail restraining device and weld delivery unit takes up asufficiently small volume of space that the truck can be fitted withroom for the welder itself, control devices; generator; and gas bottles;as well as the welding robot mounted on the unit.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevation of an alternative embodiment of the railrestraining device.

FIG. 2 is a side elevation of an alternative embodiment of the railrestraining device.

FIG. 3 is a top plan view of an alternative embodiment of the railrestraining device.

FIG. 4 is a front elevation of the rail weld containment device.

FIG. 5 is a top plan view of the rail weld containment device.

FIG. 6 is a sectional view of an alternative embodiment of the welddelivery unit.

FIG. 7 is a top plan view of an alternative embodiment of the welddelivery unit.

FIG. 8 is a side elevation of the guide rod of an alternative embodimentof the weld containment device.

FIG. 9 is a front elevation of the guide rod of an alternativeembodiment of the weld containment device.

FIG. 10 is a side elevation of the cam guide of an alternativeembodiment of the weld containment device.

FIG. 11 is a front elevation of the cam guide of an alternativeembodiment of the weld containment device.

FIG. 12 is a top plan view of the preferred rail restraint device.

FIG. 13 is a front elevational view of the preferred rail restraintdevice.

FIG. 14 is a sectional view of the preferred rail restraint deviceshowing the clamping arms in open and closed positions.

FIG. 15 is an enlarged section of the twist pin and cam adjustment ofthe weld containment device.

FIG. 16 is a side elevation of the preferred twist pin of the weldcontainment device.

FIG. 17 is a front elevation of the preferred twist pin of the weldcontainment device.

FIG. 18 is a side elevation of the preferred cam guide of the weldcontainment device.

FIG. 19 is a front elevation of the preferred cam guide of the weldcontainment device.

FIG. 20 is a rear elevation of the preferred embodiment of the welddelivery unit.

FIG. 21 is a side sectional view of the preferred embodiment of the welddelivery unit.

FIG. 22 is a top plan view of the preferred embodiment of the welddelivery unit.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The rail welding fixture consists of the rail restraint assembly 1 andthe weld containment device 290. The weld containment device 290prevents the molten metal from flowing out of the web and head areasduring the welding. In a sense, this device is an automaticallypositionable and removable mold for welding. The weld delivery unit 100is the truck and the robot lift, as well as the ancillaries such asgenerator, gas bottles, tools, etc.

The rail welding fixture in a prototype and alternative embodiment hasrail restraint 1 (FIGS. 1-3) which provides the structure on which afixed clamp 2 and movable clamp 3 are mounted in pairs. One of saidclamp pairs will engage the end of each of the respective rail sectionsto be welded. The preferred embodiment will be described in greaterdetail insofar as its elements may be delineated. The alternativeembodiment has several features which may be advantageously adapted toother embodiments, although the preferred embodiment uses, for example,hydraulic rather than mechanical actuation. In certain circumstances,the mechanical actuation described herein may be advantageous.

In this alternative embodiment, moveable clamp member 3 has an eccentricpivoting action around pin 7 which can be clamped in place by the actionof handwheel 11 fastened to screw 6 with wheel locking mounting 12,thence acting in turn on clevis pins 5 and 9 through link pin 8 and link4 and rollers 13, fastened by nut 14. This acts through bushing 10ultimately on the pad 16 carried on ball 15 providing clamping action onthe web of the rail. A horizontal plate supports the device on the crownof the rail.

Another alternative feature relates to alignment of the rails' ends toline up their respective center lines as accomplished through theclamping force on each of the four pads on the respective two clamps.Rails may also be distorted and out of line in a twisting manner. Therespective clamps are provided with a base twist assembly 17 mounted onone of the frame members of the rail welding fixture. The rail weldingfixture components are mounted with a variety of fasteners 18-24.

In this alternative embodiment, base twist assembly 17 bears at an anglethrough a shaft 25 on a pad 26 that engages the base 27 of the rail 28.In this manner, the two rail ends 30, 31 can be precisely aligned bothwith a calculated gap 32 and in vertical and transverse directions toenable the next step of the operation utilizing the weld containmentdevice.

The second component in the preferred system is the weld containmentdevice 290 which works integrally with the rail restraint 201, fittingon frame 270 thereof While preferably used together, and providingunique advantages in combination, weld containment device 290 may besuitable for other welding operations, merely providing its advantagesin compactness and rapid deployment.

The weld containment device 290 (FIGS. 4-5) is a separate part of therail welding fixture 200 and is placed into the rail restrainingassembly 201, specifically being mounted (FIG. 12) on four locating pins286 on frame 270. It is clamped to the rail restraint 201 using fourclamps 287 for securing.

The weld containment device 290 is set up on a rigid frame 291. Twoyokes 293 are actuated by a pair of cylinders 297 mounted exterior toframe 291 and the cylinder rods are connected to the yokes 293 causingthem to move inwardly. Cylinders 297 are operated through pressuretransmitted in hydraulic fittings 298 in the ordinary manner ofhydraulic operation. The yokes are mounted on two linear bearings orbushings 300 secured to the yoke using shoulders 301. Other fasteners,such as snap rings, might be suitable, but need to have adequatestrength. The bearings 300 slide on two hardened steel shafts 302. Theshafts cause the motion of the yoke to be precisely linear and parallelwith each other.

A twist pin 259 is rigidly connected to the block holders 292 throughthe use of pins 299 preventing rotation of the twist pin 295. Coolingblocks 310, preferably constructed of copper, are connected to the blockholders 292 by a plurality of fasteners 304 and 305. The cooling block310 and block holder 292 are the major components in the swingingcomponents referred to generally as the quadrants 294.

A smaller non-moving cooling block 306 is held to the frame 291 by aplurality of fasteners 307. As the cylinder extension causes the motionof the yokes inward from the open position to the closed position, theaction of the twist pins 259 engaged by the cam guide 296 causes arotation of the quadrants 294. The scope of the swing may be as littleas about 15 degrees to about 30 degrees with about twenty degreescurrently preferred.

In the preferred embodiment, in FIGS. 4-5 and FIGS. 15-19, adjustment ofthe precise rotation of the cam guides 296 is provided through the useof an adjustable hub device 295. This device 295, which is commerciallyavailable and is sold under the trademark Trantorque, uses twin taperedshaft segments 308, 309 to impinge on the cam guide 296 while at thesame time impinging on the hole in the frame 291. This operates in amanner analogous to a collect, release of the load on the tapered shaftsegments 308, 309, by loosening adjusting nut 311, permitting movementof the guides 296.

Precise adjustment of the cam guides 296 provides for a tighteningeffect as the blocks 3 10 contact the rail on the extend stroke. Acompliant fit of the blocks 310 against the rail 28 is provided by apair of springs 303 in each block.

Cooling blocks 310 and 306, when in place on the rail, provide for awelding head aperture 314 through which the welding head can fill therail web and head as described below, even when the blocks are closedand the shoe quadrants touch on the extend stroke.

During the return stroke, the yoke 293 pulls the quadrants 294 back byengaging a shoulder 317 on the twist pin shaft 318. This shoulder 317holds the quadrant in relative proximity while still allowing a rotationabout shaft 318. Since the twist pins 259 are fixedly fastened to thequadrants, parting of the containment shoes is accomplished by pullingthe pins apart. The clearance is preferably somewhat less than about oneand one half inches (1.5″) thereby providing access to the rail gap 32of about 1 inch, yet providing a level of preload on the yoke andquadrant arrangement.

An early prototype pin or rod 45 for right hand travel is shown in FIGS.8 and 9. Cam portion 65 has twist to provide 30 degrees rotation in ¾inch travel. Shaft portion 66 is provided with groove 67 to receive ring53. Knurled or splined portion 68 abuts head 69. Preferably about thirtytwo teeth will be formed in splined portion 68. Head 69 fits in aperture70 in holder 72. A press fit into aperture 70 is anticipated. At thequadrant end, set screw 52 also serves to firmly fix the unit inposition. In certain embodiments, a large number of small profilesplines could be used with mating splines in the frame 291 to enablesome level of adjustment by removal and replacement at a differentalignment. This would enable mechanical adjustment but would be limitedin the increments available by the size and number of splines. Thepreferred arrangement permits adjustment in infinite increments and isexpected to be adjustable in the field.

The early prototype cam guide 46 in FIGS. 10-11 has a body portion 80and aperture 82 with opposed lobes 84 receiving cam portion 65. Lobes 84could be formed with a profile enabling them to receive either the rightor left hand cam portions 65. For improved strength and precision,however a left and right cam guide could also be provided.

The preferred twist pin 259 (FIG. 16) is designed to have about 15degrees of rotation in about three quarters inch (¾″) of linear travel.This limit has been evaluated as an operative range, however, as of thefiling date of this application, it is believed that 20 degrees may bepreferred. The difference in the drawings is not expected to besignificant in light of the disclosure herein of the prototype whichused 30 degrees of rotation in the same length of travel. One set oftwist pins 259 and cam guides 296 will have right hand travel and theother set 259 L and 296 L left-hand travel (FIG. 5).

Preferred twist pin 259 and cam guide 296 for right hand travel is shownin FIGS. 16-19. Cam portion 315 is shown having a twist of 15 degreesrotation in three quarters inch (¾″) travel. As described above, 20degrees may be preferred. Shaft portion 316 is provided with a shoulder317. Shaft end 318 provides for insertion into the block holders 292 andthrough bushing 297 and securement with pins 259.

Cam guide 296 has a body portion 330 aperture 332 with opposed lobes 334receiving cam portion 315. Preferably lobes 334 can be formed with aprofile enabling them to receive either the right or left hand camportions 315. For improved strength and precision, however a left andright cam guide could also be provided. The degree of twist will conformto that of the corresponding pin 259, 259L.

Unlike the prior art, this geometry for operating quadrants 294 permitsoperation in very close clearance locations. The combination oflongitudinal movement of yokes 293 into and out of engagement and theoutward swinging of block holders 292 on horizontal, longitudinallyaligned shafts 302 and pins 259 enables adequate clearance for thewelding head to move reciprocally and vertically to weld the rail basestogether, while closing the blocks to maintain the welding material inthe web, and thence such clearance as is necessary to weld the head ofthe rail. This movement provides for both effective welding and compactsize. Previously difficult to gas arc weld locations such as rail inturnouts and frog joints can be welded, when they could not easily bewelded under prior art apparatus, methods, or fixtures.

The blocks 310 conform to the profile of the rail 28 for the purpose ofcontaining molten material as the weld progresses. The welding operationwill be accomplished by the following steps: placing a ceramic base moldbelow the rail base; placing the selected metal on the ceramic; and thencommencing the welding operation whereby approximately one inch (1″) gapbetween the rail ends is filled by welding material.

Using a continuous precisely controlled welding cycle will move thewelding element back and forth across the gap resulting in the fillingof the gap with metal material having mechanical properties commensuratewith that of the metal in the rail itself. To control this weld, thetransverse distance the welding element will travel at the base being along distance, while only a short distance of travel is necessary in theweb portion, the blocks will be swung out of the way of the weldingelement at the beginning of the weld. As the welding operationprogresses in a vertical manner through the web of the rail, the blockswill be closed on the web to maintain the molten material in place. Theweld will progress up the web while the blocks provide the requiredcontainment yet also providing the necessary clearance for the weldingelement. This movement can be controlled and coordinated by processingdata on positioning and the like received from a robotic controller.

A specific welding procedure will be a function of the welding unitused, which is not a part of this invention. For example, arc weldingcould be used, while theoretically, gas welding or aluminothermicbonding may be adapted to take advantage of certain aspects of theinvention, such as the rail restraint or weld containment. The preferredwelding method would be arc welding. However, great flexibility isprovided by the invention adaptable to the metallurgy of the rails, theequipment available, and the equipment in operation at any particulartime.

One possible weld delivery unit 100 shown in FIGS. 6-7 will have a frame102 mounted in truck 104. A vertical support piece 106 fits sliding rack108. Vertical support piece 106 at its lower portion 108 supportshorizontal cradle 110 adapted to have rail engaging bogie wheels 112.Thus, the device can be raised for transportation, maintenance, or thelike, and lowered for alignment on the railroad rails to reduce the loadon the structure and steady the unit for operation and enable indexingto an adjacent continuous rail, the welds along any given section ofrail being staggered as between the left and right rails.

The weld delivery unit 100 has sufficient volume of space to receive thewelder 114 itself, control devices 116 generator 118 and gas bottles; aswell as the welding robot 122 mounted on the unit 124 retracted in thebody of the truck for protection and ease of transportation.

As taught in FIGS. 6-7 the weld delivery unit is basically indexed tothe rails 28 by virtue of cradle 110 and bogie wheels 112. This providesan advantage in quick movement and lack of bracing or other connectionto the roadbed. In certain conditions this type of alignment could havesignificant utility. However, the preferred method is to now support therail restraint 201 using stabilizing legs and screw assembly 280 andthis structure can then be used as a reference for calibrating thewelder, using touch sensing plates 279.

The preferred rail welding fixture 200 has a rail restraint 201 (FIGS.12-14) which provides the structure on which the fixed clamp 202 and themovable clamp 203 are mounted in pairs. One of said clamp pairs wouldengage the end of each of the respective rail sections to be welded.Fixed clamp 202 has downwardly depending arm 205 with a clamping memberincluding a pad 223 that provides a base against which the rail 28 canbe clamped, and provides the requisite electrical contact as may berequired by the welding operation. These are paired for each clampassembly.

The movable clamp member 203 with downwardly depending arm 219 has aneccentric pivoting action around pin 207 which can be clamped in placeby the action of a cylinder 211. The rod 225 of cylinder 211 is fastenedto a clevis 208 and pinned to a link 210 with a pin 209. The rotation oflink 210 is constrained by link adjustment assembly 213 which iscomposed of a rotating structural beam 212, a screw 214 penetratingthrough the beam 212 with a rotary joint 215 connected to the clevis 208and pin 209 using a block 217. Block 217 rotates around pin 209. Theforce applied by the cylinder acts through the clevis pin 209 with avariable reaction force taken by the shoulder bolts 220 directing aclamping force downward against moveable clamp. The structural beam 212is held in the rail restraint 201 using shoulder bolts 220.

It will be seen that said arm 203 has an inverted L shape with pin orpivot 207 being located proximate the end of the short leg of the L. Pin221 provides the second pivot, this being located proximate theintersection of the short leg of the L and the long leg of the L.Clamping pad 225 is located at the end of the long leg of the L.

The length of this link adjustment assembly 213 is controlled byrotation of a handwheel 206 attached to the screw 214. The length of thefinal adjustment length of the link adjustment assembly 213 is held inplace using check nut 222 for locking.

Link adjustment assembly 213 provides one arm in a scissors arrangementwith link 210 providing a second arm and the top portion 218 of clamp203 a third. The extension or retraction of cylinder 211 acting on pivot209 results in the pivoting of link adjustment assembly at pin 209 andbolts 220. Link 210 pivots at pins 209, 221 and portion 218 around pins207, 221 results in exertion of a substantial clamping force owing tothe fixed positions of pins 207 relative to bolts 220 in beam 212.

The force applied by the cylinder acts through the clevis pin 209 with avariable reaction force taken by the shoulder bolts 220 directing aclamping force downward against moveable clamp 203 and carried on ballunit 224 fastened by nut 226. The cylinder is mounted in the beam 212 ofrestraint 201 with cylinder mounting pins 204.

Stabilizing legs 274 are adjustable and provide additional stability ofthe rail restraint support. The legs 274 are allowed to slide in thebushing 275 and held in place with setscrews 276 which may alternativelybe actuated with wingnuts (FIG. 13) or handles (FIG. 12) or otherappropriate manual gripping end. The rail restraint 201 is lifted intoplace by the use of two handles 277 located apposite each other on thetop of the frame 270.

By comparison to the alternative embodiment, the use of legs 274provides a platform fixed relative to the ground or roadbed. Thisenables the use of various bars, clamps and jacks, familiar to one inthe track art, which may be hooked or otherwise fixed to a rail andjacked against the ground or roadbed to directly control twist. Inaddition to the greater precision of alignment this also enables trackworkers to use familiar alignment and adjustment tools as may benecessary to specific jobs.

In robotic welding operations, touch sensing plates 279 are attached toblocks 278 which are attached to the frame 270 to allow the roboticcontroller to establish the location of the rail restraint 201 andthence the weld gap by touching the plates with an electrically livetorch tip. Pluralities of these plate assemblies are mounted on theframe 270 for accurate location of the weld gap. Around the perimeter ofthe frame 270 are located a plurality of windscreens or flaps 281 forprevention of ambient winds affecting the gas shield of the weldingprocess.

The rail restraint 201 is supported on the rail using jacking screwassemblies 280 in which handle 282 rotates screw 283 mounted in a fixedhorizontal plate 286 by threading, and having rotary shoes 284 attachedto the end of screw 283. Shoe 284 is positioned so as to be centered onand bear against the head of the rail 28. In this manner, clockwiserotation of a right hand threaded screw 283 will raise rail restraint201.

Improvements in the preferred embodiment when compared to our earlierprototype include the use of the hydraulic cylinder 210 and scissorsmechanism; use of adjustable legs 274 and screw assembly 280 andaddition of touch sensing blocks 278 and wind screens 281 for superiorweld control.

The preferred weld delivery unit 400 (FIGS. 20-23) will consist of acommon truck chassis 402 specially equipped to be operable on railroadrails by use of front and rear rail-engaging bogies 404. Mounted on thetruck chassis 402 is a van-style cargo box 406, which houses andprotects all of the associated process equipment. The process equipmentincludes a welder 408, a robot 409 (mounted on its side), a robotcontroller 410, and an induction heating system 412.

Auxiliary equipment includes an electric power generator 414, drivenfrom the truck engine through a power take-off transmission 416 anddrive shaft 418 through a right angle gear box 420 and a belt drive 422.Gas bottles 424 for welding shielding gas are also provided. A hydraulicsystem 428 belt-driven from the truck engine provides hydraulic power tooperate the rail restraint 201 and weld containment device 290. Varioustools and devices to assist in alignment of the rail are also stored onboard in tool case 432 and storage rack 434. A drop-down tool shelf 436allows for temporary storage of frequently used tools and supplies.

The cargo box is stabilized by use of external stabilizer legs 438 whichare hydraulically operated to keep the cargo box from swaying anddisrupting the robot orientation while welding.

The robot 408 is mounted to a horizontally moving machinery ways 426,which acts to extend the robot from the interior of the truck to thewelding position on the exterior. It will be seen that the robot, as isknown to one in the robotics art, has a base 430 mounted to rotationalbearing 432 which enables the robot to rotate around a rotational axis434. As is typical of robot devices, robot 408 has articulated arm 436which is articulated to bearing 432 and base 430 having a series ofjoints 438 and, for this application, terminates in welder head 440.While the robot 408 is typical in that it operates in three dimensionsusing controller 410, the initial orientation of robot 408 provides amajor departure from known art. Base 430 and in particular axis 434 arehorizontal, rather than their heretofore known vertical orientation.This orientation provides considerable advantages in use in the field ina mobile, portable welding apparatus. Instead of a workpiece beingbrought to and located proximate a fixed robot, this apparatus bringsthe welder to the workpiece—in this case railroad rails 28—and usesinterfacing with rail restraint 201 to automatically weld the rails. Theuse of touch sensing plates 279 enables controller 410 to preciselyalign and operate the welder head 440 to form a precisely controlled andmetallurgically sound weld on extremely long rails and in very tightspaces. The alignment of axis 434 coaxial with the longitudinal axis ofthe vehicle also provides benefits in retraction for protection andadded mobility.

Thus the device may be moved to a safe position for transportation, andstorage. It may also be extended for maintenance or for welding of therails. The robot has sufficient operating area to reach both the rightand left side rails in turn. Thus the robot can be readily and quicklystored or deployed for use. The robot receives its control power andancillary service via a cable track 430.

We claim:
 1. A rail restraining, weld containment and weld deliveryapparatus for enabling the joining of a first rail end and a second railend, each end being formed in a sectional profile with a rail base, arail web and a rail head, said apparatus comprising: a first frame forsupporting a clamp and a weld containment apparatus and adapted foraligning a welding head; said clamp adapted for restraining the firstand second ends; said weld containment apparatus connected to said clampand engageable with said ends by movement having a pivotal andlongitudinal component; a mobile weld delivery unit delivering anautomated welder having a welder head proximate said ends so that a weldcan be made joining said ends.
 2. The invention of claim 1 and saidapparatus is operable in an environment in which clearance betweenadjacent rails is about 7 to 11 inches.
 3. The invention of claim 1 andsaid weld containment apparatus being pivotally operated by use of a camactuated linear pin in which longitudinal movement of the pin impartspivotal movement in quadrants, said quadrants having cooling blocksmounted thereto.
 4. The weld containment apparatus of claim 3 furthercomprising: said quadrants being pivotally connected to yokes; saidyokes being slidably mounted on longitudinal shafts said shafts beingmounted on a frame member, such that longitudinal movement of yokes onsaid shafts impart inward and outward pivotal swinging of saidquadrants; said inward and outward pivotal swinging enabling theengagement of cooling blocks with said ends during welding and alsoenabling movement for clearance for the welding head to movereciprocally and vertically to weld the rail bases together, whileclosing the blocks to maintain the welding material in the web, andthence swinging to provide such clearance as is necessary to weld thehead of the rail.
 5. The weld containment apparatus of claim 4 furthercomprising: said pin having a fixed end and a cam end opposite saidfixed end; said fixed end being fixed relative to said quadrant, andbeing pivotable in said yoke; said cam end fitting a cam mounted in saidframe member, such that said longitudinal movement is imparted from saidframe to said yoke, and as said frame member moves longitudinallyrelative to said yoke, said cam imparts rotational movement in said end,said end rotating said pin and said fixed quadrant, thereby engaging anddisengaging rail welding cooling blocks from said rail ends.
 6. The weldcontainment apparatus of claim 5 further comprising: said cam end beingformed and arranged with between about 15 to 30 degrees twist in threequarters of one inch travel; said cam being formed and arranged withbetween about 15 to 30 degrees twist in three quarters of one inchtravel.
 7. The apparatus of claim 5 further comprising: said railrestraint having a first frame for supporting a clamp and adapted tosupport a weld containment apparatus and further adapted for aligning awelding head, said clamp adapted for restraining the first and secondends; said first frame having a fixed downwardly depending arm and amovable downwardly depending arm spaced therefrom defining a railreceiving space therebetween; said movable arm is eccentrically pivotedon said frame to enable capturing of a rail in said space; said movablearm being pivoted about a first pivot and a clamping force being appliedto and released from a second pivot displaced from said first pivot;said frame supporting a third pivot and said third pivot connecting witha link to said second pivot whereby an actuating force applied to saidlink transmits said clamping force through said link; said link being ascissors link; said scissors link having a fourth pivot joining a firstpart connected to said third pivot and a second part connected to saidsecond pivot, said actuating force being applied at said fourth pivot;said mobile weld delivery unit having a vehicle body and a welder; saidwelder being retractably and deployably carried in said body; saidwelder being automatically controlled by a controller, said controllercalibrating the operation of said weld relative to the location of saidrails; said weld operation calibration being performed based on touchsensing members located on said rail restraint; said vehicle having alongitudinal axis; said welder and controller coacting with a robotdevice to position a welder head based on said calibrated reference;said robot device having a base and a main axis, said main axis beingaligned with the vehicle longitudinal axis.
 8. The rail restraint ofclaim 1 further comprising: said first frame having a fixed downwardlydepending arm and a movable downwardly depending arm spaced therefromdefining a rail receiving space therebetween; said movable arm iseccentrically pivoted on said frame to enable capturing of a rail insaid space.
 9. The rail restraint of claim 8 further comprising: saidmovable arm being pivoted about a first pivot and a clamping force beingapplied to and released from a second pivot displaced from said firstpivot.
 10. The rail restraint of claim 9 further comprising: said framesupporting a third pivot and said third pivot connecting with a link tosaid second pivot whereby an actuating force applied to said linktransmits said clamping force through said link.
 11. The rail restraintof claim 10 further comprising: said link being a scissors link; saidscissors link having a fourth pivot joining a first part connected tosaid third pivot and a second part connected to said second pivot, saidactuating force being applied at said fourth pivot.
 12. The railrestraint of claim 11 further comprising: said clamp being a firstclamp, said first clamp being disposed adjacent a first end of saidframe; said frame having a second clamp disposed at a second end of saidframe, said second end being opposite said first end; said second clampbeing in form and operation analogous to said first clamp.
 13. The railrestraint of claim 10 comprising: said arm having an inverted L shapewith said first pivot being located proximate the end of the short legof the L the second pivot being located proximate the intersection ofthe short leg of the L and the long leg of the L and a clamping padbeing located at the end of the long leg of the L.
 14. The railrestraint of claim 13 further comprising: said actuating force beingapplied to said link by force application means for imparting forceacting between a mounting pin and said fourth pivot.
 15. The railrestraint of claim 14 further comprising: said clamp being a firstclamp, said first clamp being disposed adjacent a first end of saidframe; said frame having a second clamp disposed at a second end of saidframe, said second end being opposite said first end; said second clampbeing in form and operation analogous to said first clamp.
 16. The welddelivery unit of claim 1 further comprising: said mobile weld deliveryunit having a vehicle body and a welder; said welder being retractablyand deployably carried in said body; said welder being automaticallycontrolled by a controller, said controller calibrating the operation ofsaid weld relative to the location of said rails.
 17. The weld deliveryunit of claim 16 further comprising: said weld operation calibrationbeing performed based on touch sensing members located on said railrestraint.
 18. The weld delivery unit of claim 17 further comprising:said vehicle having a longitudinal axis; said welder and controllercoacting with a robot device to position a welder head based on saidcalibrated reference; said robot device having a base and a main axis,said main axis being aligned with the vehicle longitudinal axis.
 19. Theweld delivery unit of claim 18 further comprising: said weld deliveryunit including an induction heater for preheating said rails prior towelding.
 20. A weld containment apparatus for enabling the joining of afirst rail end and a second rail end, each end being formed in asectional profile with a rail base, a rail web and a rail head,comprising: said weld containment apparatus being connectable to a clampand engageable with said rail ends by movement having a pivotal andlongitudinal component; said weld containment apparatus further beingpivotally operated by use of a cam actuated linear pin in whichlongitudinal movement of the pin imparts pivotal movement in quadrants,said quadrants having cooling blocks mounted thereto.
 21. The weldcontainment apparatus of claim 20 further comprising: said quadrantsbeing pivotally connected to yokes; said yokes being slidably mounted onlongitudinal shafts said shafts being mounted on a frame member, suchthat longitudinal movement of yokes on said shafts impart inward andoutward pivotal swinging of said quadrants; said inward and outwardpivotal swinging enabling the engagement of cooling blocks with saidends during welding and also enabling movement for clearance for thewelding head to move reciprocally and vertically to weld the rail basestogether, while closing the blocks to maintain the welding material inthe web, and thence swinging to provide such clearance as is necessaryto weld the head of the rail.
 22. The weld containment apparatus ofclaim 21 further comprising: said pin having a fixed end and a cam endopposite said fixed end; said fixed end being fixed relative to saidquadrant, and being pivotable in said yoke; said cam end fitting a cammounted in said frame member, such that said longitudinal movement isimparted from said frame to said yoke, and as said frame member moveslongitudinally relative to said yoke, said cam imparts rotationalmovement in said end, said end rotating said pin and said fixedquadrant, thereby engaging and disengaging rail welding cooling blocksfrom said rail ends.
 23. The weld containment apparatus of claim 21further comprising: said cam end being formed and arranged with betweenabout 15 to 30 degrees twist in three quarters of one inch travel; saidcam being formed and arranged with between about 15 to 30 degrees twistin three quarters of one inch travel.
 24. A rail restraining, apparatusfor enabling the joining of a first rail end and a second rail end, eachend being formed in a sectional profile with a rail base, a rail web anda rail head, said apparatus comprising: a first frame for supporting aclamp and adapted to support a weld containment apparatus and furtheradapted for aligning a welding head; said clamp adapted for restrainingthe first and second ends; said first frame having a fixed downwardlydepending arm and a movable downwardly depending arm spaced therefromdefining a rail receiving space therebetween; said movable arm iseccentrically pivoted on said frame to enable capturing of a rail insaid space; said movable arm being pivoted about a first pivot and aclamping force being applied to and released from a second pivotdisplaced from said first pivot; said frame supporting a third pivot andsaid third pivot connecting with a link to said second pivot whereby anactuating force applied to said link transmits said clamping forcethrough said link.
 25. The rail restraint of claim 24 furthercomprising: said link being a scissors link; said scissors link having afourth pivot joining a first part connected to said third pivot and asecond part connected to said second pivot, said actuating force beingapplied at said fourth pivot.
 26. The rail restraint of claim 25 furthercomprising: said clamp being a first clamp, said first clamp beingdisposed adjacent a first end of said frame; said frame having a secondclamp disposed at a second end of said frame, said second end beingopposite said first end; said second clamp being in form and operationanalogous to said first clamp.
 27. The rail restraint of claim 24further comprising: said arm having an inverted L shape with said firstpivot being located proximate the end of the short leg of the L thesecond pivot being located proximate the intersection of the short legof the L and the long leg of the L and a clamping pad being located atthe end of the long leg of the L.
 28. The rail restraint of claim 27further comprising: said actuating force being applied to said link byforce application means for imparting force acting between a mountingpin and said fourth pivot.
 29. The rail restraint of claim 28 furthercomprising: said clamp being a first clamp, said first clamp beingdisposed adjacent a first end of said frame; said frame having a secondclamp disposed at a second end of said frame, said second end beingopposite said first end; said second clamp being in form and operationanalogous to said first clamp.
 30. A rail weld delivery apparatus forenabling the joining of a first rail end and a second rail end, each endbeing formed in a sectional profile with a rail base, a rail web and arail head, said apparatus comprising: a mobile weld delivery unitdelivering an automated welder having a welder head proximate said endsso that a weld can be made joining said ends; said mobile weld deliveryunit having a vehicle body and a welder; said welder being retractablyand deployably carried in said body; said welder being automaticallycontrolled by a controller, said controller calibrating the operation ofsaid weld relative to the location of said rails; said weld operationcalibration being performed based on touch sensing members located onsaid rail restraint; said vehicle having a longitudinal axis; saidwelder and controller coacting with a robot device to position a welderhead based on said calibrated reference; said robot device having a baseand a main axis, said main axis being aligned with the vehiclelongitudinal axis; said weld delivery unit including an induction heaterfor preheating said rails prior to welding.